wanna ask i just doing the pnp for my 20ve . but i using other head to do pnp then i take all my shims install to the new head with my sr16ve . after that i found out the shims clearance got problem. and now i need to buy 3mm shimz? is it using other head and rocker will get this problem ? or i change my sr20ve to sr16ve cam the shimz sr20ve not suitable? thanx for help